Harry M. Reid (D-Nev.), who was elected Senate majority leader yesterday, said last night that President Bush still has not grasped the urgent need to change course in Iraq. Reid vowed to press quickly for phased troop withdrawals, a more international approach to Iraq's problems and a rebuilding of the depleted U.S. military.

In his first extensive interview since the Senate Democrats' leadership election, Reid also said members of his party will have to think big on the nation's domestic issues. That includes tackling the budget deficit with strict new rules on spending, exploring an eventual expansion of Medicare to address the uninsured, and examining an increase in tax rates on upper-income Americans.

But it was on the issue of Iraq that he was most passionate. Voter anger over the war swept his party to power with the unlikely defeat of six Republican senators, he said. Democrats must respond to that anger, he added, with hearings to keep the heat on the Bush administration, and with calls for a regional Middle Eastern conference and a revitalized Iraqi reconstruction effort.

To that end, he said, one of the first acts of the new Democratic Congress will be a $75 billion boost to the military budget to try to get the Army's diminished units back into combat shape.

Democrats will not try, Reid pledged, to play the strongest hand they have -- using Congress's power of the purse to starve the war effort of money and force the president to move. Such an effort would only elicit a veto from Bush. But he said Democrats will marshal their newly acquired power -- in hearing rooms and on the Senate floor -- to stoke public opinion and drive the debate.

"Three Americans killed yesterday, four British; 150 Iraqis taken out of that building and kidnapped; 1,800-plus went through that one Baghdad morgue but that doesn't count all the dead," Reid recounted. "My displeasure with the president, he doesn't understand the urgency of this. It's all victory for him, but I don't know what that means anymore in Iraq. I do know what we are doing now doesn't work."

Reid said he will be able to work well with Nancy Pelosi (D-Calif.), the incoming House speaker, whom he described as resilient and "a very astute politician." But he said the Senate will work differently from the House, given the Senate Democrats' very narrow 51 to 49 majority, which will necessitate close cooperation with Republicans.

"The speaker of the House has to be aggressive," Reid said. "It's like the British Parliament. If you've got the votes, you ram it through. But the Senate works differently."

Democrats also elected Sen. Richard J. Durbin (Ill.) yesterday as assistant Senate majority leader. Durbin has been assistant minority leader since January 2005. Senate Republicans will elect their leaders for the 110th Congress today.

In January, after two years as a Senate minority leader who bedeviled the Republican legislative agenda and sharply criticized Bush, Reid will take the helm of a body that has been notoriously difficult to control.

To the casual observer, Reid comes across as a reserved, soft-spoken, deferential politician who appears more comfortable in the backrooms of the Capitol than in the spotlight. But to those who have watched him close up, Reid's reputation is quite different -- that of a brawler who moves with the alacrity he acquired in his days as an amateur boxer.

The consummate pessimist in a political world full of sunny optimism, Reid is fond of saying that he would rather expect the worst and accept the occasional pleasant surprise than forever live with disappointment.